1. Field of the Invention
The invention relates to an electronic device in which a semiconductor unit that generates heat when operating is housed in a case, and that is provided with a passage through which coolant that cools the semiconductor unit flows inside the case.
2. Description of Related Art
Technology in which an inverter or a DC-DC converter or the like is formed by a semiconductor unit combined with a semiconductor device is known. A semiconductor unit that forms an inverter or the like for a large amount of power generates heat when operating, and thus needs to be cooled. Japanese Patent Application Publication No. 2011-177004 (JP 2011-177004 A) describes technology that cools a semiconductor unit by fixing the semiconductor unit to a flow path forming body. A coolant passage with an open upper surface is formed in the flow path forming body, and when the semiconductor unit is fixed to the flow path forming body, the coolant passage is closed off by the semiconductor unit, and coolant flows while contacting the semiconductor unit. The semiconductor unit must be electrically connected to an external device such as an electric motor. With the technology described in JP 2011-177004 A, a terminal is fixed to the semiconductor unit. This terminal is connected to a semiconductor inside the semiconductor unit, and a bolt hole is formed in the terminal. A conductor that extends toward an external device is fixed to the terminal by screwing a bolt into this bolt hole.
With the technology described in JP 2011-177004 A, the semiconductor unit is exposed, and the terminal is also exposed. Because the terminal is exposed, a special design is not needed to fix the conductor that extends toward the external device to the terminal. The bolt simply need be screwed into the bolt hole. The semiconductor unit is preferably housed inside of the case to improve durability and reliability of the inverter and the like. When the semiconductor unit is housed in a case, a coolant passage must be provided inside the case. Also, a conductor that extends from inside to outside the case through a wall of the case (hereinafter, this conductor will be referred to as an “external output bus bar”) is needed to connect the semiconductor unit to the external device, and this external output bus bar must be connected inside to the case to a conductor on the semiconductor unit side (hereinafter this conductor will be referred to as a “bus bar”).